A Case of Foraminal Disc Herniation Successfully Treated via Paraspinal Transpars Approach

A 61-year-old man presented with an excruciating pain in the right lower extremity. The pain was aggravated by a short distance walk and lateral bending to the right. These symptoms implied right L4 radicular pain. Magnetic resonance images revealed foraminal disc herniation at the right L4-5 level. After failure of conservative treatment, the patient underwent surgery via the paraspinal transpars approach. Following exposure of the right lateral edge of the L4 lamina, we partially resected a part of the pars interarticularis in accordance with the preoperative simulation using a 3-dimensional printed bone model. Fragmented discs compressing the dorsal root ganglion of L4 nerve root were totally removed. Postoperative computed tomography showed complete preservation of the facet. The patient showed remarkable relief from the pain and returned to his job a week after the surgery. Foraminal disc herniations cause fierce leg pain and are often intractable to conservative treatment. Selection of the surgical approach is often a matter of debate. The paraspinal transpars approach was effective and a less invasive surgical method in that it can preserve the facet joint. A three-dimensional printed bone model was useful in determining the minimal resection range of the pars interarticularis

ラット頭蓋骨由来間葉系幹細胞移植は脊髄損傷モデルラットにおいて機能回復をもたらす

広島大学(Hiroshima University)博士(医学)Doctor of Philosophy in Medical Sciencedoctora

A novel bone-thinning technique for transcranial stimulation motor-evoked potentials in rats

Abstract Transcranial electrical stimulated motor-evoked potentials (tcMEPs) are widely used to evaluate motor function in humans, and even in animal studies, tcMEPs are used to evaluate neurological dysfunction. However, there is a dearth of reports on extended tcMEP recordings in both animal models and humans. Therefore, this study examined a new technique for stably recording tcMEPs over several weeks in six healthy female Sprague–Dawley rats. We thinned the skull bone using the skull base and spinal surgery technique to reduce electrical resistance for electrical stimulation. tcMEPs were recorded on days 1, 7, 14, 21, and 28 after surgery. The onset latency and amplitude of tcMEPs from the hindlimbs were recorded and evaluated, and histological analysis was performed. Stable amplitude and onset latency could be recorded over several weeks, and histological analysis indicated no complications attributable to the procedure. Thus, our novel technique allows for less invasive, safer, easier, and more stable extended tcMEP recordings than previously reported techniques. The presently reported technique may be applied to the study of various nerve injury models in rats: specifically, to evaluate the degree of nerve dysfunction and recovery in spinal cord injury, cerebral infarction, and brain contusion models

Establishment of longitudinal transcranial stimulation motor evoked potentials monitoring of the forelimbs and hindlimbs in an ischemic stroke rat model

Abstract Evaluation of motor function ischemic stroke rat models includes qualitative assessments such as the modified neurological severity score (mNSS). However, mNSS cannot evaluate the function of forelimbs and hindlimbs separately. We quantitatively assessed motor function in a middle cerebral artery occlusion (MCAO) rat model of ischemic stroke. We recorded transcranial stimulation motor evoked potentials (tcMEPs) from MCAO rats and measured the changes in onset latency and amplitude at the forelimbs and hindlimbs up to 28 days after stroke. All MCAO subjects showed hemiparesis. The amplitudes of tcMEPs in both fore- and hindlimbs were inversely correlated with mNSS scores, but the amplitudes in the forelimbs improved later than those in the hindlimbs. The onset latency of tcMEPs in the forelimbs and hindlimbs remained almost unchanged during the follow-up period. Our results showed the differences in tcMEPs amplitude recovery times between the forelimbs and hindlimbs after MCAO, which emphasizes the importance of separately evaluating forelimbs and hindlimbs in post-ischemic stroke models. This minimally invasive and longitudinal quantitative method could be useful for further research on diseases and neurogenesis

Effectiveness of tuning an artificial intelligence algorithm for cerebral aneurysm diagnosis: a study of 10,000 consecutive cases

Abstract Diagnostic image analysis for unruptured cerebral aneurysms using artificial intelligence has a very high sensitivity. However, further improvement is needed because of a relatively high number of false positives. This study aimed to confirm the clinical utility of tuning an artificial intelligence algorithm for cerebral aneurysm diagnosis. We extracted 10,000 magnetic resonance imaging scans of participants who underwent brain screening using the “Brain Dock” system. The sensitivity and false positives/case for aneurysm detection were compared before and after tuning the algorithm. The initial diagnosis included only cases for which feedback to the algorithm was provided. In the primary analysis, the sensitivity of aneurysm diagnosis decreased from 96.5 to 90% and the false positives/case improved from 2.06 to 0.99 after tuning the algorithm (P < 0.001). In the secondary analysis, the sensitivity of aneurysm diagnosis decreased from 98.8 to 94.6% and the false positives/case improved from 1.99 to 1.03 after tuning the algorithm (P < 0.001). The false positives/case reduced without a significant decrease in sensitivity. Using large clinical datasets, we demonstrated that by tuning the algorithm, we could significantly reduce false positives with a minimal decline in sensitivity